The character is described as the big bad of Season 3, part of an interpretation of the infamous World Killer storyline from the pages of the DC Comics. Though the character is based on the comics, the costume for Annable’s TV character will be different from the DC version.

According to the DC Comics description, Reign was one of five Worldkillers created by Zor-El, who later came to regret his part in the creation of those blood-thirsty, super-powerful monsters. Reign and her partners survived Krypton, but her origin remained a mystery even to her. In the comics, Reign becomes an enemy of Supergirl when she arrives on Earth, with plans to conquer it.

“Greg (Berlanti) and I have wanted to work with Odette for years,” said executive producer Andrew Kreisberg. “We are beyond excited to have her join our cast in the scary, powerful and heartbreaking role of Reign.”

Annable, who most recently played Dr. Zoe Brockett in CBS’ medical drama series Pure Genius, previously played another doctor, Jessica Adams on hit Fox series House. She also starred on ABC limited series Astronaut Wives Club and recurred on Fox comedy The Grinder. Her previous credits also include series Banshee and features You Again and Cloverfield. She’s repped by UTA and Untitled Entertainment.